The "one-and-a-half" minimally invasive transforaminal lumbar interbody fusion: a single-center retrospective case series.

Abstract

Symptomatic lumbar spondylolisthesis with multilevel spinal stenosis poses a complex surgical challenge, often managed through multilevel decompression and fusion. There is a hybrid surgical approach, termed "one-and-a-half," that combines minimally invasive transforaminal lumbar interbody fusion (mTLIF) at the unstable segment with unilateral laminotomy for bilateral decompression (ULBD) at an adjacent stenotic level without fusion. The aim of this study was to assess the reoperation rate, specifically fusion extension to adjacent decompressed segments, in patients who underwent the one-and-a-half mTLIF technique. This retrospective analysis reviewed patients who underwent one-and-a-half mTLIF performed by a single surgeon between January 2016 and February 2023 at a single institution. The revision surgery rate, as well as radiographic and clinical outcomes, was assessed. Thirty-three patients (57.6% male, mean age 67.9 years) who underwent one-and-a-half mTLIF were included, with a median follow-up of 26 months. Fusion was achieved in 96.2% (25/26) of patients. The reoperation rate was 9.1% (3/33); 2 patients (6.1%) required subsequent fusion at the previously decompressed (ULBD-treated) level and 1 patient (3.0%) at the index level. The perioperative complication rate was 12.1% (4/33), and neurological complications were not observed. The one-and-a-half mTLIF technique is a promising alternative to traditional multilevel fusion in patients with lumbar spondylolisthesis and concurrent multilevel stenosis. This hybrid approach offers a biomechanically stable alternative to multilevel fusion by selectively fusing the unstable segment while preserving spinal motion through decompression alone at the adjacent stenotic level. This study highlights its long-term effectiveness in reducing the necessity for reoperation and fusion extension, suggesting one-and-a-half mTLIF as a less invasive yet durable solution for managing complex lumbar spine pathology with promising radiographic and clinical outcomes.